In your OP you mention new lights - was the tank stable before the addition of the lights, and has it been stable since you changed the lights?

My "bible" for algae identification is Aquarium Algae ID. There is quite a large section there on green water and many suggestions for solving it. I had a quick read and my earlier suggestion of riding it out may not be a good way forward - think I got it mixed up with the brown algae.

Yup definitely green water, that probably one of the hardest to battle from what I hear. I think a UV sterilzer would be the most effective method to the problem accompanied with large water changes. For the long term some heavy Bio filtration might solve the problem.

I've had Green Water in Paradise (before Phoenix), and it was a 70GAL tank. My problem initially was high powered lighting, not enough fast growing plants from the beginning. In essence there was an imbalance of light, nutrients and heat which lead to the green water issue. At first I put in some Daphina (these worked wonders) but it kept coming back.

Eventually, I planted the devil out of it, did daily 10% water changes and it cleared up as the tank balanced. As for the Daphia, they reproduced enough until I put fish in which quickly made short work of them.